GE advances energy neutrality for municipal wastewater treatment

By GE | September 28, 2015

With the energy used by water and wastewater treatment plants in the U.S. accounting for 35 percent of a typical local government’s energy budget, GE today formally introduced its new ZeeLung Membrane Aerated Biofilm Reactor (MABR) technology that is four times more energy efficient than existing aeration systems. Aeration for biological treatment is the largest energy consumer in a wastewater treatment plant, typically representing 60 percent of a facility’s power usage.

GE developed the ZeeLung technology to enable wastewater treatment plants to achieve energy neutrality by significantly reducing the energy demand of the largest consumer in a treatment plant—biological process aeration. Coupling this energy reduction with enhanced on-site energy production from advanced anaerobic digestion can achieve energy neutral wastewater facilities—where the energy produced equals or exceeds the energy consumed.

“By inventing ZeeLung, GE is creating an opportunity to transform wastewater treatment plants from disposal facilities to resource recovery centers that yield clean water, nutrients and renewable energy from wastewater,” said Heiner Markhoff, president and CEO—water and process technologies for GE Power & Water. “This is a game-changing innovation in the pursuit of energy neutrality in the municipal wastewater treatment sector that also addresses the need for facilities to upgrade for nutrient removal and capacity expansion within an existing plant footprint.”

Municipal wastewater treatment plants are among the biggest industrial users of energy because they operate 24 hours a day, seven days a week. Publicly owned wastewater treatment systems use 75 billion kilowatt hours of energy annually, which is enough electricity to power 6.75 million homes. More than 3 percent of all electricity in the United States is used for wastewater treatment.

In conventional biological treatment, fine bubble aeration is used to deliver oxygen to the microorganisms that metabolize the nutrients and organic pollutants in the wastewater. However, this approach is not efficient since most of the oxygen is wasted. To make this process more efficient, GE’s technology team developed the ZeeLung technology, which transfers oxygen by diffusion to a biofilm that grows on the outside surface of the membrane. The microorganisms in the biofilm remove nutrients and organics in the wastewater by metabolizing them in the presence of oxygen. The result is a four times reduction in energy compared to conventional fine bubble aeration systems in use today.